One type of lock used to control access to a container or other similar article is a plastic lock comprising a body portion and a link portion comprising an arcuately shaped portion having two integral parallel legs. The body portion has two passageways extending therethrough with an indentation in each passageway. The legs of the link portion are shaped to be able to be pushed through the passageways and are provided with a resilient projection. As the legs are pushed through the passageways, the resilient projections are compressed until they reach the indentations in the passageways and move into such indentations so as to be locked in position. The indentations and projections are designed to prevent movement only in one direction which is to prevent pulling of the legs out of the passageways after they have been locked. The arcuately shaped portion limits further inward movement of the legs after the projections have reached the indentations. When it is desired to gain access to the container, the portions of the legs between the arcuately shaped portion and the body portion are cut. The remaining portions of the legs are then pushed through the passageways and are then discarded with the arcuately shaped portion. The body portion is kept to be used with a new link portion to control access to another situation. The cost of the body portion is significantly greater than the cost of the link portion. This is primarily due to the manufacturing cost to form the indentations in the passageways. In one method of forming the body portion, two parts of a mold are moved in linear directions between an opened or a closed position and when in a closed position, they form a cavity. At least one of these mold parts contains a pair of fixed arms utilized to form the passageways. In addition, one of the mold parts contains a pair of rods having a controllable movement perpendicular to the fixed arms and locatable adjacent thereto so as to form the indentations in each passageway. The movable rods are moved through one part of the closed mold into the appropriate position in the cavity while the mold is in the closed position. After the plastic material has been injected into the closed mold and cured, the movable rods are first withdrawn and then the two part mold is moved to the opened position and the formed body portion is removed. This method forms the necessary indentations in the passageway but also forms two openings in the body portion which then have to be sealed over. Thus, there existed a need for a new more economical system for forming such body portions.